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The Exposure Risk Assessment of Residual Pesticides in Tea (다류에 존재하는 잔류농약 노출 안전성 평가)

  • Kim, Jae-Kwan;Oh, Moon-Seog;Kim, Ki-Yu;Kim, Yeong-Su;Son, Mi-Hee;Bae, Ho-Jung;Kang, Chung-Won;Park, Young-Bok;Yoon, Mi-Hye;Lee, Jong-Bok;Jeong, Ju-Yeon
    • The Korean Journal of Pesticide Science
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    • v.15 no.1
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    • pp.28-35
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    • 2011
  • The investigation of 218 residual pesticides for 19 types of tea (persimmon leaf tea, chrysanthemum tea, green tea, lavender tea, rosemary tea, dandelion leaf tea, puer tea, mulberry leaf tea, hydrangea leaf tea, jasmine tea, nuomixiang tea, buckwheat tea, mugwort tea, lotus leaf tea, oolong tea, longjing tea, rose tea, tiehkwanyin tea and huoguo tea) obtained from markets in Ansan and Suwon was carried out to assess the risk for residual pesticides in tea. The detection rate was 23.1 % (19 samples of total 65 tea samples) and the detected pesticides were 15 pesticides, such as bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon and triazophos. The range of concentrations for the detected residual pesticides was 0.01 to 1.24 mg/kg which showed below their maximum residue limits (MRL), but the residual concentration of bifenthrin in a puer tea showed above the legal limit of 0.3 mg/kg. The result of risk assessment of residual pesticides for the detected 15 samples showed that EDI (estimated daily intake) of the pesticides detected ranged 0.0001~0.0844% of their ADI (acceptable daily intake).

Antioxidant and Synergist Effect of Extract Isolated from Commercial Green, Oolong and Black Tea (시판 녹차, 홍차, 오룡차의 항산화 및 상승효과)

  • 이호선;손종연
    • The Korean Journal of Food And Nutrition
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    • v.15 no.4
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    • pp.377-381
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    • 2002
  • The antioxidative effect of tea extracts from green tea, oolong tea and black tea was investigated. The extraction yields of crude catechin were green tea 5.4%, oolong tea 3.5%, and black tea 2.5%. Green tea, oolong tea and black tea of crude catechin showed antioxident activity at concentrations of 200ppm, and the oolong tea showed highest antioxidant effect. The browning intensities(at 420 nm) of green, oolong and black tea were 0.140, 0.582 and 0.915, respectively and green tea showed highest hydrogen donating ability(HDA) and than followed by oolong or black tea. Also, when the crude catechin(100 ppm) was used in combination with ${\alpha}$-tocopherol(50 ppm) and ascorbyl palmitate(50 ppm), the crude cathechin showed very strong synergistic effect, comparable to that of crude catechin(200 ppm).

Analysis of Newspaper Articles on Korean Style Medicinal Tea (한방차에 관한 신문기사 내용 분석)

  • Park, Soyeon;Lee, Sanglock;Chae, Seungbum;Lee, Sangjae
    • Journal of Society of Preventive Korean Medicine
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    • v.21 no.2
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    • pp.95-103
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    • 2017
  • Objectives : The aim of this study is to analyze the news contents of Korean style medicinal tea and investigate how it is portrayed in the consumer market. Methods : Total of 355 articles are selected by inputting "Korean style medicinal tea" and analyzed; 108 articles for 2013, 107 articles for 2014, 140 articles for 2015. Results : 175 different tea were found from Jan. $1^{st}$ 2013 to Dec. $31^{st}$ 2015, with ginger tea the most frequently covered for 68 times. Among 175 tea, 117 had one ingredient and 58 had more than one ingredient. The most frequently covered category was "Disease and Health Promotion" followed by "Commercial Ads", "Korean style medicinal tea Culture", and others. From 355 articles, 188 provided the information on the efficacy of Korean style medicinal tea, 88 presented the pharmacological activity, 84 addressed the recipe, 80 explained the taste, and 31 included ancient literature. The most frequently covered tea were ginger tea, omija tea, gugija tea, jujube tea, mogwa tea. Autumn and winter had 109 articles, spring had 89, and summer had 86. Conclusions : This study showed the potential of Korean style medicinal tea as a successful future content. Most of the articles about Korean style medicinal tea contained information about the efficacy but practical information such as the recipe and drinking method were not addressed much. Therefore, future study is needed to investigate additional information about Korean style medicinal tea.

A Comparison of the Antioxidant Activity of Barley Leaf Tea and Green Tea according to Leaching Conditions in Distilled Water (침출 조건에 따른 보리잎차와 녹차의 항산화능 비교)

  • Jang, Jae-Hee;Choi, Hee-Sun;Cheong, Hyo-Sook;Kang, Ok-Ju
    • Korean journal of food and cookery science
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    • v.23 no.2
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    • pp.165-172
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    • 2007
  • This study was conducted to investigate the antioxidant amounts and properties of barley leaf tea and green tea at under various leaching conditions. The leaching temperatures and times of the distilled water were 50, 70 and $90^{\circ}$C for 1, 3 and 5 min, respectively. The levels of crude fat and ash in the barley leaf tea were higher than those in green tea. Brown color intensity and flavonoid absorbance increased with leaching temperature. The highest vitamin C levels and water-soluble phenol resulted at $90^{\circ}$C for 3 min. The DPPH radical scavenging activities of the barley leaf tea and of green tea were 11.06 and 50.56%, respectively, compared to 2.9% for L-ascorbic acid (150 ppm). The nitrite scavenging activities of barley leaf tea and green tea were 95.11 and 74.88%, respectively. The SOD-like activities of barley leaf tea, green tea, and L-ascorbic acid (150 ppm) were 12.99, 8.33, and 12.75%, respectively. The antioxidant effect of green tea was higher than that of barley leaf tea and lastly, the SOD-like activity of barley leaf tea was as high as that of green tea.

Effect of Green Tea and Pueraria radix Tea on Apolipoprotein B100 Production and Low Density Lipoprotein Activity

  • Lee, Jeong-Sook
    • Preventive Nutrition and Food Science
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    • v.8 no.3
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    • pp.284-288
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    • 2003
  • In this study, we investigated the effects of green tea and Pueraria radix tea on the production of Apo B$_{100}$ in Hep G$_2$ liver cells and on the expression of the low density lipoprotein (LDL) receptor. Treatment with green tea resulted in a 60.7% decrease on the Apo B$_{100}$ concentration in Hep G$_2$ cells. Pueraria radix tea decreased Apo B$_{100}$ concentration by 63.5% in Hep G$_2$ cells. Green tea and Pueraria radix tea significantly decreased Apo B$_{100}$ concentration by 64.8% and 61.8%, respectively, in the media. Treatment of the cells with green tea and Pueraria radix tea also significantly decreased the intracellular total cholesterol, but total cholesterol concentrations in the media increased by 26.4% (green tea) and 23.6% (Pueraria radix tea) above that measured in the media of control cells. The addition of green tea and Pueraria radix to the media of the Hep Gz cells increased the LDL receptor binding activities by 84.1% and 79.4%, respectively.

A Study on Chlorophyll and Ascorbic Acid Contents of Korean and Japanese Green Tea (한국 및 일본산 녹차(茶)의 Chlorophyll 및 Ascorbic Acid의 함량 비교)

  • Byun Jae-Ok;Kim Mi-Hyang
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.1
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    • pp.107-112
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    • 2006
  • This study analyzed the changes of chlorophyll and ascorbic acid contents according to the extraction temperatures and the number of soakings using five kinds of Korean and Japanese green tea(3 kinds of green tea and 2 kinds of tea bag) which were obtained from local markets in Korea and Japan. The findings are as follows: 1. The chlorophyll contents of Japanese green tea were $2\sim3$ times higher than those of Korean green tea. 2. The chlorophyll contents of Korean green tea in high and middle grades were increased with increasing temperature $(80>70>60^{\circ}C)$ but the contents in low grade were increased with decreasing temperature. The contents of chlorophyll in Japanese green tea were almost similar in low, middle and high grades. 3. Ascorbic acid content was higher in low grade Korean green tea but it was higher in high and middle grades of Japanese green tea. Chlorophyll contents of Japanese green tea were higher than those of Korean green tea but ascorbic acid contents of Korean green tea were higher than those of Japanese green tea.

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Effects of Dried Leaf Powders, Water and Ethanol Extracts of Persimmon and Green Tea Leaves on Lipid Metabolism and Antioxidative Capacity in 12-Month-Old Rats (감잎, 녹차의 건분 및 물, 에탄올추출물이 노령쥐의 지방대사와 항산화능에 미치는 영향)

  • 오현명;김미경
    • Journal of Nutrition and Health
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    • v.34 no.3
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    • pp.285-298
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    • 2001
  • The effects of dried leaf powders and water and ethanol extracts of persimmon and green tea on lipid metabolism, lipid peroxidation and antioxidative enzyme activity were investigated in 12-month-old rats. Forty-nine male Sprague-Dawley rats weighing 520$\pm$19g were blocked into seven groups according to body weight. Rats were raised for four weeks with control(no tea leaf powder or extracts) and experimental diets containing either 5%(w/w) dried leaf powders of persimmon(Diospyros kaki Thunb) or green tea(Camellia sinensis O. Ktze), or water or ethanol extract from equal amounts of each dried tea powder. Food intakes of all tea diet groups were higher than that of control. Weight gains and food efficiency ratios of all tea diet groups were not significantly different from those of control. All tea diets decreased plasma triglyceride level, especially, green tea powder and persimmon ethanol diets were more effective than other diet. All the tea diet groups showed decrease in liver triglyceride level, and persimmon powder and ethanol extract increased fecal triglyceride excretion. Plasma cholesterol levels of all the tea diet groups were not significantly different from the control, but control. Fecal cholesterliver cholesterol concegroups were significantlntrations of all tea y lower than that of ol excretions of persimmon powder, green tea ethanol extract, persommon ethanol extract and green tea ethanol extract groups were significantly higher than that of control. Plasma and liver thiobarbituric acid reactive substance(TBARS) concentrations of all the tea diet groups were lower than that of control. Especially, plasma TBARS concentrations of green tea powder and persimmon ethanol extract groups were sinificantly low. Red blood cell(RBC) superoxide dismutase(SOD) activities of persimmon ethanol extract and green tea water extract groups were increased, and RBC catalase activities of all experimental groups were not significantly different. RBC glutathione peroxidase(GSH-px) activities of persimmon ethanol extract, persimmon water extract and green tea powder groups were increased. Liver SOD activities of all the tea diet groups except green tea ethanol extract group were higher than that of control. Liver catalase activities of all experimental groups were not significantly different, and liver GSH-px activity of green tea powder group was significantly higher than that of control. In conclusion, dried leaf powders, and water and ethanol extracts of persimmon and green tea were effective in lowering lipid level, inhibiting lipid peroxidation and increasing antioxdative enzyme activities in 12-month-old rat. Green tea leaf powder with high contents of flavonoids and water soluble dietar fiber was most effective in lowering plasma triglyceride, cholesterol and TBARS level. (Korean J Nutrition 34(3) : 285~298, 2001)

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Bioavailability and Efficiency of Ten Catechins as an Antioxidant

  • Shi, John
    • Preventive Nutrition and Food Science
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    • v.7 no.3
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    • pp.327-331
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    • 2002
  • Tea is a pleasant, popular and safe beverage in the world. During the past decade, epidemiological studies have shown that tea catechins intake is associated with lower risk of cardiovascular disease. Tea provides a dietary source of health-promoting components to help humans reduce a wide variety of cancer risks and chronic diseases. The antioxidative activity of tea-derived catchins has been extensively studied. The antioxidant effect is a synergistic action between catechins e.g. EGCG, EGC, ECG, EC, pheophytins a and b, and other components in tea leaves, which aye more bioavailable for human body. Green tea has a Higher content of catechins than other kinds of tea. Green tea extract with hot water has high potential and more efficiency to reduce cancer risk than any other tea products or pure EGCG. Protein, iyon, and other food components may interfere with the bioavailability of ten catechins. Interaction of catechins with drug affects the cancer-preventive activity of some cancer-fighting medication. Further studies are required to determine the bioavailability of tea catechins and cancer-preventive functionality.

Major Compositions of Leaf Tea and Flower Tea Using Native Camellia(Camellia japonica) in Korea

  • Cha, Young-Ju;Lee, Jang-Won;Park, Min-Hee;Hwang, Eun-Ju;Lee, Sook-Young
    • Proceedings of the Plant Resources Society of Korea Conference
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    • pp.33-33
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    • 2003
  • Most of leaf teas, except flower tea, were considered as good materials with basic conditions for tea manufacture because water content was below 6 %, Crude protein was the greatest component in roasted young leaf tea, crude fats in roasted mature leaf tea and ashes in fermented young leaf tea. Caffein were present as the highest amount(5.18%) in steamed mature leaf tea, showing less amount than greenp teas. Catechin were contained as the highest amount in all kinds of teas, especially fermented young leaf tea. was the highest(9.57%). Tannin, which highly related with tea quality including astringent taste, color and perfume, were present as the highest amount in fermented young leaf tea.(중략)

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Studies about Monoamine Oxidase Inhibitory Activities of Korean Green Tea (Teae sinensis L.) Harvested from Different Time and Location

  • Choi, You Jin;Chong, Han-Soo;Kim, Young-Kyoon;Hwang, Keum Hee
    • Natural Product Sciences
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    • v.19 no.4
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    • pp.281-285
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    • 2013
  • This study was designed to investigate the nervous sedative effects of green tea. The sedative effect was evaluated by examination of Monoamine oxidases (MAOs) inhibitory activity in vitro in the brain and liver of rat fed on green tea cultivated and harvested from the different regions and periods. It showed that methanol extracts of green tea inhibited significantly the brain MAO-A activity. Especially late harvested green tea extracts showed potential inhibitory activity. The liver MAO-B activity was also inhibited by all of the green tea extracts with strong intensity. This study confirmed that major compounds of green tea such as catechin, epigallocatechin-3-gallate (EGCG) and L-theanine, which were well known for the main bioactive components in the tea plants, were not associated with the MAO inhibitory activities of green tea. These results suggested that a MAO inhibition activity comes from other minor tea components we have to search in the future.